As of today, the first house designed and built to the Passivhaus standard in Arlington is now on the market. The million-dollar home — referred to as the Arlington Passivhaus — was built by Southern Exposure Homes, a builder run by brothers Eric and Roger Lin, with an emphasis on airtightness and energy efficiency. But there’s also a 700-square-foot green roof, contemporary interior finishes, and landscape that reduces stormwater runoff.